Comparing Polyphenolic Yields from the Crowberry <i>Empetrum nigrum L.</i> on the Basse-Côte-Nord Du Québec via Solvent and Microwave-Assisted Extractions

Wildberries are recognized worldwide for their nutrition potential, especially for polyphenols such as anthocyanins and flavonoids, which are known as antioxidants. The crowberry, Empetrum nigrum found in northern climates, is a wildberry that has the potential to be used in natural health and cosmetics products due to its high antioxidant activity. This study is focused on antioxidant active crowberries collected from the Basse-Côte-Nord in the province of Québec. The crowberries were analyzed by techniques suitable for a remote region such as the Basse-Côte-Nord, which has limited access to chemicals, equipment and transportation. Two different extraction processes were examined: conventional methods, such as solid-liquid extraction, and unconventional extraction methods such as microwave-assisted extraction. Multiple parameters were tested, including solvent type, solvent-water ratios, liquid/solid ratios, time and temperature. The extracts were analyzed using the Folin-Ciocalteu reagent assay for total phenolic compounds, the pH differential method for total monomeric anthocyanins and the 2,2-diphenyl-1-picrylhydrazyl free radical method for antioxidant activity. The results indicated that, although the ethanol mixtures with water solvent generally gave the highest yield, water extraction gave a significant yield as well. Results also indicated that, compared to the solid-liquid extraction method, the microwave-assisted extraction method allowed for generally smaller liquid:solid ratio (75:1 mL/g compared to 25:1 mL/g with the exception of antioxidant activity) and therefore less solvent. It also allowed for less extraction time (1–5 h compared to 5 min).